Hepatic encephalopathy

Date Updated: 05/31/2025

Overview

Hepatic encephalopathy (huh-PAT-ik en-sef-uh-LOP-uh-thee) is a serious condition that occurs when the liver is unable to filter toxins from the blood, including ammonia from the intestines. A buildup of toxins affects the brain's ability to function. If left untreated or not treated successfully, hepatic encephalopathy can lead to unresponsiveness, coma or death.

Hepatic encephalopathy may be caused by injury to the liver, cancer or a chronic liver disease that results in liver failure, such as cirrhosis. Hepatic encephalopathy occurs in 30% to 40% of people who have cirrhosis. Alcohol use, infections, use of some medicines and blood clots in the veins also may cause hepatic encephalopathy.

Prompt treatment is needed for hepatic encephalopathy to prevent death. Call 911 or emergency medical help if you think you or a loved one might have hepatic encephalopathy.

Types

There are three types of hepatic encephalopathy:

Type A. Type A hepatic encephalopathy results from acute liver failure, which is loss of liver function that happens quickly — in days or weeks.
Type B. Type B hepatic encephalopathy happens when blood that should go to the liver through the portosystemic shunt instead goes into the bloodstream. The shunt is an opening between the portal vein and the hepatic vein, which carries blood from the liver to the heart.
Type C. Type C hepatic encephalopathy occurs in people who have cirrhosis, which is advanced scarring of the liver. People with acute-on-chronic liver failure, which is rapid decline in people with chronic liver failure, also may have type C.

Acute hepatic encephalopathy comes on suddenly. Chronic hepatic encephalopathy is long-lasting. People who have hepatic encephalopathy may have a wide range of cognitive or mental changes, which range from barely noticeable to coma. When symptoms are noticeable, the condition is called overt hepatic encephalopathy. When symptoms are not noticeable, the condition is called covert encephalopathy.

Symptoms

Common symptoms of hepatic encephalopathy include:

Trouble focusing or paying attention.
Not knowing where you are.
Sleepiness during the day or trouble sleeping at night.
Memory loss or confusion.
Flapping tremor in the limbs.
Personality or mood changes.
Slurred speech or movement.
Falling into a coma.

Over time, the symptoms of hepatic encephalopathy can lead to a lower quality of life and ability to function. Having other chronic conditions besides hepatic encephalopathy may make daily life even harder.

When to see a doctor

If you or someone with liver disease has sudden confusion, cannot wake up or displays unusual behavior, call your healthcare professional or go to a hospital emergency room right away.

Causes

Hepatic encephalopathy is caused by a buildup of toxins, especially ammonia, when the liver can't filter waste from the blood. This buildup may result from:

Alcohol use and conditions that arise from it, such as cirrhosis.
Imbalances of electrolytes in the body, such as a low potassium or low sodium level.
Infections.
Bleeding in the digestive tract.
Complications from a liver transplant.
Surgery placing shunts in the liver to improve blood flow.

Other factors that may cause hepatic encephalopathy include:

Certain medicines, such as diuretics, opioids and sedatives.
Dehydration arising from vomiting, diarrhea or other causes.
Constipation.
Older age.

Risk factors

You're more likely to develop hepatic encephalopathy if you have:

Diabetes.
Advanced liver disease, such as cirrhosis.
Kidney disease.
Epilepsy.
Low muscle mass, sometimes called sarcopenia.
Large portosystemic shunts in your liver.
Low sodium or high ammonia levels in your blood.
Certain genetic risk factors.

You're also at higher risk of hepatic encephalopathy if you:

Are an older adult.
Drink alcohol.
Have poor eating habits.
Take diuretics, proton-pump inhibitors, opioids or benzodiazepine medicines.
Have a history of hepatic encephalopathy.

Your healthcare professional may tell you about other risk factors based on your health or lifestyle.

Complications

Some complications from hepatic encephalopathy may be very serious. Common complications include:

Trouble with daily life or work.
Falls and injuries.
Lasting memory and attention problems.
Trouble driving a car.
Sleep disturbances.
Hospitalizations.
Coma.
Death.

Prevention

It's possible to reduce your chances of getting hepatic encephalopathy by taking care of your health. Some ways to prevent hepatic encephalopathy include:

Take prescription medicines as prescribed.
Eat protein from plants and dairy.
Avoid alcohol and sedating medicines.
Avoid opioids.
Stay hydrated.
Prevent constipation.
Treat infections as soon as they appear.
Get regular checkups for liver disease.

Diagnosis

Hepatic encephalopathy is diagnosed by looking at the medical history, signs and symptoms, medicine use, and the results of blood tests and other tests. Tests and procedures that may be used to diagnose acute liver failure include:

Psychological exam. Tests that look for thinking skills may be used when symptoms are hard to detect, such as in covert hepatic encephalopathy. A test that involves naming animals is one such test.
Neuropsychological tests. Tasks that involve the use of pencil and paper can be used to assess thinking, motor skills, speed and hand coordination. The Psychometric Hepatic Encephalopathy Score is one such test. Tests that check reaction time to sounds, such as the continuous reaction time test, also may be used.
Blood tests. Blood tests for ammonia, electrolytes, glucose level, C-reactive protein and other markers can help rule out other conditions that have similar symptoms, such as diabetes and stroke. Blood tests also show whether infections or use of alcohol or medicines are a factor.
Electroencephalogram, also called EEG. An EEG measures electrical activity in the brain. This helps healthcare professionals understand the severity of the condition.
Imaging tests. A CT scan or MRI that looks at the liver and blood vessels may be done to rule out stroke, seizures or other causes. Scans of the gut area may show issues with liver blood flow.

Stages

The West Haven criteria are used to classify severity of disease. There are five grades, also called stages, of hepatic encephalopathy:

Grade 0. There are no symptoms, and hepatic encephalopathy is found only by tests.
Grade 1. Typical symptoms include sleep issues, mild confusion and mood swings.
Grade 2. Disorientation and unusual behavior are common in grade 2. Daytime drowsiness also may be present.
Grade 3. Extreme confusion and sleepiness are typical, though the person can still respond to others.
Grade 4. A type of coma called hepatic coma is present, and the person cannot respond to others.

Grade 0 and grade 1 are known as covert hepatic encephalopathy because in these stages, the condition may not be noticeable. Grades 2 to 4 are called overt hepatic encephalopathy because the symptoms are noticeable.

In the early stages of hepatic encephalopathy, it may be hard to assign a grade. Family members living with someone who is ill may be able to help healthcare professionals by talking about behavior changes that are part of hepatic encephalopathy.

In advanced stages of hepatic encephalopathy, the Glasgow Coma Scale may be used to assess verbal and physical response to sound, touch and other stimuli in people who aren't conscious.

Treatment

Though hepatic encephalopathy may lead to death, it may be treatable if caught early. Knowing why it occurred and treating the cause of hepatic encephalopathy is a key part of treatment. You will need the help of your care team to manage hepatic encephalopathy.

Around 30% to 40% of people with cirrhosis develop hepatic encephalopathy. It must be treated daily to avoid further decline in health.

Treatment usually requires locating the source of infection or bleeding and treating it. If the bout of hepatic encephalopathy is severe, treatment in the intensive care unit, also called ICU, may be needed. In the ICU, your care team will closely monitor you and treat complications that arise, such as pneumonia.

Medications

Several medicines may be used to treat hepatic encephalopathy, including:

Lactulose. Lactulose lowers the level of ammonia by increasing bowel movements. It also may improve the health of your gut, making recovery easier. Lactulose may be given orally or in an enema.
Rifaximin (Xifaxan). Rifaximin is an antibiotic that kills bacteria in the gut. In people who have overt hepatic encephalopathy, it may reduce the risk of having more bouts in the future.
L-ornithine L-aspartate (LOLA). This compound is given to reduce the level of ammonia in the body.
Polyethylene glycol laxatives. Laxatives that contain polyethylene glycol may be given to empty the bowel quickly. These laxatives also are called PEG laxatives.

Taking a zinc supplement may help convert ammonia into other compounds that can pass out of the body.

Surgery or other procedures

Depending on the grade and severity of the condition, your healthcare team may recommend surgery or other procedures to treat hepatic encephalopathy.

Bowel enema. If you have constipation or are dehydrated, a bowel enema may be given to restore hydration.
TIPS surgery. Placement of a transjugular intrahepatic portosystemic shunt, also called TIPS, may improve blood flow, but it also may worsen hepatic encephalopathy in some people. If you have TIPS, you take medicine after surgery to lower the chance that hepatic encephalopathy happens again.
Liver transplant. A liver transplant is a procedure to replace the liver with a healthy liver from a deceased donor or with part of a liver from a living donor. Liver transplant may reverse hepatic encephalopathy. It may be the best option for people who have had overt hepatic encephalopathy and the only option for people who have end-stage liver disease.

The best time to have a liver transplant varies. Your care team can order several tests to see if transplantation is an option for you. Depending on where you live, hepatic encephalopathy may not be a condition that allows you to be placed on a waiting list for transplant.

Lifestyle and dietary changes

Changes in diet and eating habits may reduce the risk of future bouts of hepatic encephalopathy.

Medication changes. Your care team may adjust medicines that you take for other conditions to reduce the risk of falls or other harms.
Vitamins. If you also lack necessary nutrients, a multivitamin supplement may be given to improve overall health.
Dietary changes. Eating a healthy diet may help you manage hepatic encephalopathy or conditions that cause it, such as cirrhosis. Ask your care team whether a different diet can help you before making changes.
Changes in meal timing. Eating small meals during the day may improve mental performance and make it easier to take lactulose. Your care team can help you set up a meal schedule.
Regular exercise. Becoming fitter may improve your health and ability to sleep well. Your care team may have you start an exercise program to build strength, improve balance or gain endurance. Usually, you will start with short sessions of easy movement and do more as you gain strength.
Home modifications. Creating a safe living space can reduce your risk of falls and injuries.

Hepatic encephalopathy is a complex condition. Treating hepatic encephalopathy at a less severe grade may not reduce the risk of having a more severe case later. Even if treatment of hepatic encephalopathy is successful, in most cases, you will still have advanced liver disease.